Crystal chemistry of phases forming super-Earth mantles

Pressures and temperatures in extraterrestrial rocky planets can reach up to 4 TPa and up to 9000 K, conditions that are hardly accessible with current experimental methods. This limitation leads to the problem of finding appropriate proxy compounds for high-pressure minerals. Therefore the ultimate goal of this proposal is reveal the role of iron oxides as structural prototypes for high-pressure silicates at pressure up to 200 GPa and temperatures up to 3000 K. We are going to synthesize iron silicates at these conditions, determine their crystal structure and compressional behavior, and characterize the oxidation and spin state of iron atoms.